Historians lament plan to fill in Petty's Run excavation in Philadelphia

To the untrained eye, the rough-looking tract on the south side of the Statehouse in Trenton looks like an ordinary construction site.

To archaeologists and historians, it's a rare treasure. Deep in the earth are the remains of what may be the only colonial-era steel mill excavated in North America.

Two Philadelphians - Timothy Matlack and Owen Biddle - once made steel at the so-called Petty's Run site, demonstrating an independent streak that dismayed England. The British wanted raw materials from the colonies so they could turn out the finished product for sale in America.

"This was part of American independence," said Ian Burrow, vice president of Hunter Research Inc. in Trenton, which conducted the archaeological dig. "We can be more self-sufficient."

Now, the uncovered ruins of the steel mill and other 18th- and 19th-century mills and buildings - built atop one another like the layers of a cake - will be reburied by spring for about $400,000.

The cost of turning the site into a publicly accessible park - estimated to be in the millions - is unaffordable when New Jersey is struggling to maintain parks it already has, state officials said.

So the State Capitol Joint Management Commission voted last month in favor of Lt. Gov. Kimberly Guadagno's order to fill in the site and protect the ruins until better economic times, when the state can revisit plans for a park....